Performance Evaluation Of Prioritized H264 Video Transmission Over Quality Of Service Aware Wireless Ad Hoc Lan

Multimedia applications like video streaming and video conferencing are increasing rapidly over wireless networks. Video data is delay-sensitive and requires more bandwidth to be sent. Wireless channel has limited bandwidth and is prone to errors due to time-varying signal strength, which limits the availability of bandwidth for these applications. Hence, video compression techniques are crucial for video applications. The H.264/AVC video coding standard is widely used for streaming applications due to its high coding efficiency and the network friendly features. Loss of different packets in a video stream induces different amounts of distortion to the video quality; therefore, video bit stream should be prioritized. The basic IEEE 802.11 MAC protocol does not provide quality of service support to the users and cannot be used as the main access mechanism for transmitting prioritized video. In this thesis, we design a cross-layer and priority aware packet fragmentation scheme which transmits pre-encoded compressed H.264 video on IEEE 802.11e EDCA based MAC layer to enhance the video quality over error-prone wireless networks. Data fragmentation modifies the packet size by adapting to the varying channel conditions and improves successful video transmission. We also study the optimal packet size to maximize the weighted goodput for different number of users and channels bit error rates.